Digitally driven audio effects generator

Abstract

A digitally driven audio effects generator includes a source of binary information and keyboard which provide digital information to a plurality of source or sink type binary drivers. A ladder matrix is coupled to the binary drivers and provides an output signal. An audio frequency signal generator responds to the keyboard and controls an interrupting switch which serrates the output signal at an audio frequency rate.

I claim: 
     
       1. A digitally driven audio effects generator comprising: a source of binary information, providing a binary encoded output signal indicative of a selected amplitude characteristic;   a source of operating potential;   a source of audio frequency signal;   digital to analog conversion means having means for receiving digitally encoded information and means for producing an analog output signal having an amplitude corresponding to said digitally encoded information;   means coupling said source of binary information to said digital to analog conversion means; and   switching means, coupled to said source of audio frequency signal and to said digital to analog conversion means, interrupting said output signal at a rate determined by the frequency of said audio frequency signal.   
     
     
       2. A digitally driven audio effects generator as set forth in claim 1 further including an electro-acoustic transducer coupled to said digital to analog conversion means. 
     
     
       3. A digitally driven audio effects generator as set forth in claim 2 wherein said digital to analog conversion means includes a plurality of resistors each having a first and a second terminal wherein said first terminals are coupled to a common node and wherein said means coupling include: a plurality of binary drivers, each having an input and output terminal, producing an output signal having one of two selected, potentials in as a function of the binary state applied to said input terminal.   
     
     
       4. A digitally driven audio effects generator as set forth in claim 3 wherein one of said second terminals of one of said resistors is connected to ground and wherein said second terminals of said remaining resistors are each connected to a selected one of said output terminals of said binary drivers. 
     
     
       5. A digitally driven audio effects generator as set forth in claim 4 wherein said switching means includes a transistor. 
     
     
       6. A digitally driven audio effects generator as set forth in claim 5 wherein said transistor includes an emitter electrode coupled to ground, a base electrode coupled to said source of audio frequency signal, and a collector electrode coupled to said source of operating potential. 
     
     
       7. A digitally driven audio effects generator as set forth in claim 6 wherein said source of binary information includes a keyboard. 
     
     
       8. A digitally driven audio effects generator as set forth in claim 7 wherein said electro-acoustic transducer includes a speaker. 
     
     
       9. For use in an educational and entertainment device including a digital electronic systems in which a plurality of audio effects are to be produced in response to user command digitally controlled audio effect means comprising: a keyboard having a plurality of operable keys;   a source of binary information coupled to said keyboard and having at least two output terminals including processor means having a stored code of instructions for supplying a binary code amplitude control signal by imposing either of two binary logic states upon said terminals in a parallel bit mode;   a resistive ladder matrix having a plurality of matrix resistors corresponding to said output terminals each coupled between one of said output terminals and a common node and a resistor coupled between said common node and ground;   a source of audio frequency signal coupled to said keyboard and producing an audio frequency signal responsive to said keys having a frequency corresponding to the selected one of said keys depressed; and   a transistor having a first electrode coupled to said source of audio frequency signal, a second electrode coupled to ground, and a third electrode coupled to said common node operative in response to said audio frequency signal to alter the volume at said common node.   
     
     
       10. Digitally controlled audio effect means as set forth in claim 9 wherein said source of binary includes four output terminals and means providing thereon four bit parallel shifted binary information, and wherein said plurality of matrix resistors numbers four.